java操作数据库

增加

     public String addParent(Parent pp) {
         Connection conn=new ConntionUtil().openConnection();
         PreparedStatement pstmt=null;
         try {
             if(pp.getUsername()!=null){
                 String sql="insert into parents(username,nickname,password,registertime,sex,birth,area,headimg,weixin_openid) values(?,?,?,?,?,?,?,?,?)";
                 pstmt=conn.prepareStatement(sql);
                 pstmt.setString(1,pp.getUsername());
                 pstmt.setString(2,EmojiUtil.Emoji(pp.getNickname()));
                 pstmt.setString(3,pp.getPassword());
                 pstmt.setString(4,pp.getRegistertime());
                 pstmt.setInt(5,pp.getSex());
                 pstmt.setDate(6,null);
                 pstmt.setString(7,pp.getArea());
                 pstmt.setString(8,pp.getHeadimg());
                 pstmt.setString(9,pp.getWeixin_openid());
                 int i=pstmt.executeUpdate();
                 if(i>0){
                     return "0";
                 }else{
                     return "1";
                 }
             }else{
                 return "0";
             }
         }catch(SQLException e){
             try{
                 conn.rollback();
             }catch(SQLException e1){
                 e1.printStackTrace();
             }
             e.printStackTrace();
             return "-1";
         }finally{
             try {
                 if(pstmt!=null) pstmt.close();
                 if(conn!=null) conn.close();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }     }

修改

     public void addData(String strdata,int intdata){
         Connection conn=new ConntionUtil().openConnection();
         PreparedStatement pstmt=null;
         try{
             String sql="update tablename set strdata=?,intdata=? where id=? ";
             pstmt=conn.prepareStatement(sql);
             pstmt.setString(1,strdata);
             pstmt.setInt(2,intdata);
             pstmt.setString(3,id);
             pstmt.executeUpdate();
         }catch(SQLException e){
             e.printStackTrace();
         }finally{
             try {
                 if(pstmt!=null)pstmt.close();
                 if(conn!=null)conn.close();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
     }

查找

     public boolean haveParent(int userId) {
         Connection conn=new ConntionUtil().openConnection();
         PreparedStatement pstmt=null;
         ResultSet rs=null;
         try {
             String sql="select parentId,parentName from user where user_id=?";
             pstmt=conn.prepareStatement(sql);
             pstmt.setInt(1,userId);
              rs=pstmt.executeQuery();
             while(rs.next()){
                 if(rs.getString("parentName")==null || rs.getString("parentName")=="" || "".equals(rs.getString("parentName"))){
                     return false;
                 }else{
                     return true;
                 }
             }
         } catch (SQLException e) {
             e.printStackTrace();
             return false;
         }finally{
             try {
                 if(rs!=null)rs.close();
                 if(pstmt!=null)pstmt.close();
                 if(conn!=null)conn.close();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
         return false;
     }